The present invention relates to an improved method and apparatus for processing sheared trees, and more particularly, to a method and apparatus capable of processing trees which are substantially longer than the travel of the apparatus.
A typical tree processing apparatus includes a carriage having a delimber head, the carriage being movable outwardly along a boom to delimb the trunk of the sheared tree. When the carriage and delimber head reaches an outermost position, a pair of topping blades are actuated to cut off or top the outer end portion of the tree trunk. The delimbed and topped tree trunk is then deposited in a bunk.
Examples of prior art methods and apparatus for delimbing and topping trees include those illustrated in U.S. Pat. No. 3,693,679 and Canadian Pat. No. 927,718. Typically, prior art processing methods and apparatus have placed a limitation on the height of the trees could be processed because of the limitation imposed on the delimbing stroke of the apparatus by the overall length of the apparatus. For example, a known prior art processing apparatus or harvester has a 32 ft. delimbing stroke. In addition, the return stroke of the delimbing head in prior art harvesters has represented "lost motion", i.e., a portion of the operating cycle which is wasted. Thus, the length limitation and the cycle time of the entire delimbing and topping operation have heretofore placed a limitation on the volume of trees which could be processed (delimbed and topped) within a given length of time.
A harvesting method and apparatus which overcomes the above-stated problems is illustrated and described in copending application Ser. No. 560,662, filed Mar. 20, 1975, in the name of Stanley C. Jasinski and Robert N. Windsor for a "Method of Processing Trees and Apparatus Used Therein". Althrough generally satisfactory in operation, the apparatus disclosed in the above-cited application requires two separate shear and delimber carriages, thus adding to the complexity and cost of the apparatus.
This device permits smaller machines to be used for processing of long trees whereas currently, in general, only huge, heavy and more costly machines have been developed for this purpose.